铜冠铜箔：公司主要从事各类高精度电子铜箔的研发、制造和销售等

Group 1 - The company, Tongguan Copper Foil, focuses on the research, manufacturing, and sales of various high-precision electronic copper foils [2] - The main products are categorized by application fields, including PCB copper foil and lithium battery copper foil [2] - The downstream industries for PCB copper foil primarily include the electronic information sector, with end applications in communication, computers, consumer electronics, and automotive electronics [2]